Field of the Invention
The present invention relates to a stator structure of a VR type resolver and to a VR type resolver having a specific winding.
Description of Related Art
For example, a resolver can be used for detecting a rotation angle of an electric motor in electric vehicles or hybrid vehicles. In this case, in a wire used for a winding of the resolver, copper or copper alloy is used as a material and polyurethane, polyester, or the like, is used as a coating. A sulfide contained in an ATF (Automatic Transmission Fluid) oil which is used for the transmission permeates the polyurethane, polyester, etc., and corrodes the copper and alloy. As a result, there is a problem in that conduction of the winding is deteriorated.
As a technology which can solves this problem, Japanese Unexamined Patent Application Laid-open No. 2009-133648 discloses an angle detector in which a coil is insulated from a surrounding atmosphere thereof by an insulating oil. In addition, Japanese Unexamined Patent Application Laid-open No. 2005-300410 discloses a resolver in which a winding is covered with waterproof resin.
In the method that uses the insulating oil, it is necessary to have a structure for enclosing the insulating oil, and therefore, production cost is increased. In addition, since the insulating oil is used in environments that are exposed to vibration, there is a problem in that the insulating oil may leak out, and the reliability thereof is decreased. In a structure in which a winding is also covered with waterproof resin, producing processes are increased and the production cost is increased. In view of such circumstances, it is an object of the present invention to provide a stator structure and a VR type resolver in which the winding of the resolver can be prevented from corroding without increasing the production cost.